High voltage electric swtich



Aug. 27, 1968 c. E. KERR, JR 3,399,286

HIGH VOLTAGE ELECTRIC SWITCH iled March 7, 1966 4 Sheets-Sheet 1 INVENTOR. CHARLES E. KERR, JR.

FIG. I BY W- ATTORNEY Aug. 27, 1968 c. E. KERR, JR 3,399,286

HIGH VOLTAGE ELECTRIC SWITCH Q Filed March 7. 1966 4 Sheets-Sheet 2 w 8 mm whmu om nm ax wa mm l g- 7, 1968 c. E. KERR, JR

HIGH VOLTAGE ELECTRIC SWITCH 4 Sheets-Sheet 5 Filed March '7. 1966 mo 5 ow mm Q 6 8 w no on INVENTOR. CHARLES, KE RR, JR.

ATTORNEY 7, 1968 c. E. KERR, JR

HIGH VOLTAGE ELECTRIC SWITCH v 4 Sheets-Sheet Filed March 7. 1966 INVENTOR. CHARLES E. KERR, JR.

VI E N Du O W A United States Patent Oregon Filed Mar. 7, 1966, Ser. No. 532,154

13 Claims. (Cl. 200-144) This invention relates to electric switches, and more particularly to electric switches for making and breaking electric circuits of high voltage and high current.

It is the principal object of the present invention to provide an electric switch by which the making and breaking of the electric circuit occurs only under high vacuum.

Another important object of this invention is the provision of an electric switch of the class described which may be utilized either for underground installation or for overhead installation.

Still another important object of the present invention is the provision of an electric switch of the class described which includes means by which to determine visually whether the switch is open or closed.

A further important object of this invention is the provision of an electric switch of the class described including means by which a plurality of such switches may be combined as a unit for operation by a single control.

A still further important object of the present invention is the provision of an electric switch of the class described which is of simplified construction for economical manufacture, which is compact in size for ease of transport and economical installation, and which has long service life of precise and faithful operation with a minimum of maintenance and repair.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings in which:

FIG. 1 is a plan view of an electric switch embodying the features of the present invention;

FIG. 2 is a view in side elevation of the electric switch shown in FIG. 1;

FIG. 3 is a longitudinal sectional view taken on the line 33 in FIG. 1, the operating components being arranged in the open position of the switch;

FIG. 4 is a fragmentary sectional view similar to FIG. 3 but showing the operating components in broken lines in the partially open position of the switch;

FIG. 5 is a fragmentary sectional view similar to FIG. 4 but with the operating components arranged in the closed position of the switch,

FIG. 6 is a foreshortened sectional view taken on the line 6-6 in FIG. 2;

FIG. 7 is a fragmentary side elevation as viewed along the line 77 in FIG. 3 showing the operating mechanism in solid lines in the fully open condition of the switch and in broken lines for the fully closed position of the switch;

FIG. 7a is a fragmentary side elevation similar to FIG. 7 but showing the operating mechanism in position for the partially open condition of the switch;

FIG. 8 is a fragmentary sectional view taken on the line 88 in FIG. 5;

FIG. 9 is a fragmentary sectional view taken on the line 9-9 in FIG. 8;

FIG. 10 is a foreshortened plan view of an operating tool for use in adjusting the electric switch; and

FIG. 11 is a fragmentary plan view showing a plurality 3,399,286 Patented Aug. 27, 1968 "ice of the electric switches of the previous views combined for simultaneous operation by a single control, portions being broken away to disclose details of internal construction.

As best illustrated in FIGS. 3 and 6, the electric switch of the present invention includes a housing defined by the end walls 10 and 11, side walls 12, top wall 13 and the removable bottom wall 14 secured to the peripheral flange 15 by the screws 16. This housing thus forms a fluidtight container capable of being filled with oil or any other desired insulating liquid or gas, through the fill pipe 17 which is closed by the removable cap 18. Expansion of insulating liquid in the housing is accommodated by the flexible diaphragm 19 which communicates with the interior of the housing through the opening 20 and which is protected on its outer side by the cover 21 which forms an expansion chamber. The margins of the diaphragms are interposed between the cover and the top wall of the housing, providing a liquidtight seal therebetween, and this assembly is secured together by such means as the screws 22.

Projecting through an opening in the end wall 11 of the housing, and appropriately sealed therein, is an electric terminal connector which includes the electrically conductive post 23, the threaded shank 24 thereof and the electrically non-conductive insulator 25 surrounding said shank. The insulator may be of porcelain, epoxy resin, or any other suitable material. The inwardly projecting end of the shank mounts a primary electric contact which in cludes the hollow sleeve 26 and the supporting hub 27. A nut 28 secures the hub removably to the shank.

In similar manner the opposite end wall 10 supports a second electrical terminal connector which includes the electrically conductive post 29, the threaded shank 30 thereof and the electrically non-conductive insulator 31 surrounding said shank. However, the inwardly projecting end of this shank connects to the outer wall 32 of an electrically conductive sleeve 33, as by means of the nuts 34.

The sleeve wall is secured to a transverse, electrically non-conductive supporting plate 35 which is mounted upon laterally spaced, elongated, electrically non-conductive rods 36. These rods extend longitudinally within the housing and are supported at their opposite ends in openings provided in the end plates 37, secured to the end walls of the housing by such means as the bolts 38.

The inner portion of the sleeve 33 is offset angularly inward, converging to constrict its inner open end. This angular portion of the sleeve is provided with a plurality of longitudinal slots 39 spaced circumferentially about the sleeve and defining between them the resilient fingers 40. These fingers form electrical contacts which slidably engage the outer surface of an elongated, hollow secondary contact member 41 made of electrically conductive material. This contact member is supported on the rods 36 by the laterally projecting perforated tabs 42 (FIG. 6) for movement relative to the sleeve 33. The sleeve and secondary contact member are disposed coaxially with respect to the common longitudinal axis of the terminal connectors.

Operating means is provided for moving the secondary contact member 41 relative to the sleeve 33 toward and away from the primary contact 26. Referring principally to FIG. 3, there is mounted pivotally on a pivot screw 43, anchored in a post 44 projecting from the secondary contact member, one end of a link 45. The opposite end of 3 the link is connected pivotally by the pivot pin 46 to one arm 47 of a bell crank lever. The shaft 48 of the bell crank lever projects outwardly through the top wall 13 of the housing (FIG. 3) and through a support bearing 49, and the outer end of this shaft supports a pair of radial pins 50 extending in diametrically opposite directions. These pins constitute the second arm of the bell crank lever, and are arranged to be received freely in the transverse slot 51 in the socket end 52 of an operating tool (FIG. This socket end is secured to one end of an elongated shank 53, the opposite end of which carries a cross bar 54 which serves as a handle for rotating the tool.

One of the projecting pins 50 also cooperates with a pair of upstanding stop members 55 (FIG. 1) projecting from the base of the bearing 49, to limit the degree of rotation of the bell crank lever so as to restrict movement of the secondary contact member 41 between the limits illustrated in FIGS. 3 and 5.

It will be understood that the outer end of the bell crank lever may be arranged for connection to a power driven operator, such as an electric solenoid, an air, bydraulic, or electric motor, or other suitable means which may, if desired, be controlled from a remote location.

Mounted slidably within the secondary contact member 41 and projecting from the end thereof facing the primary contact 26 is a vacuum interrupter. This interrupter is of conventional and well known construction and, as best illustrated in FIG. 5, includes an elongated hollow envelope 56 of glass or other electrically nonconductive material. The envelope is sealed at its opposite ends to the electrically conductive end plates 57 and 58. The end plate 57 facing the primary contact mounts a conductor member 59, as by means of the threaded studs 60 and securing nuts 61. The outer end of this conductor member is provided with an enlarged primary contactor element 62 proportioned for frictional engagement with the primary contact 26. The inner end of the conductor member is provided with an enlarged secondary contactor element 63 proportioned for frictional engagement with the end of the secondary contact member 41 facing the primary contact 26. This end of the secondary contact member is provided with a plurality of resilient fingers 64 defined by a plurality of circumferentially spaced longitudinal slots 65, in manner similar to the fingers 40 on the sleeve.

The end plate 57 facing the primary contact 26 also supports an electrically conductive stem 66 which projects into the envelope 56 and terminates at its inner end in a contact element 67. Associated with this element is a second contact element 68 formed at the inner end of a stem 69 which extends in the direction opposite the first named stem. A glass or other electrically non-conductive shield 70 surrounds these contact elements to prevent whatever spatter of metallic particles might be emitted from them from being deposited on the inner surface of the envelope 56 to cause shorting of the interrupter.

An intermediate portion of the stem 69 is sealed to the inner end of a longitudinally flexible bellows seal 71. The opposite end of the bellows is sealed to an inward projection 72 of the end plate 58. The stem 69 extends freely through the bellows seal, thence through an opening in the projection and end plate 58, and through an opening in the guide member 73 which is secured to the end plate 58 by such means as the studs 74 and nuts 75. A longitudinal frame member 76 of substantially U-shaped cross section interconnects the inner guide member 73 and the longitudinally spaced outer guide member 77. The guide members serve to support the interrupter for reciprocative movement within the secondary contact member 41.

Electrical connection between the contact 68 and the terminal post 29 is provided by a pair of electrical cables 78 and 78' in a manner described more fully hereinafter.

Means is provided for moving the vacuum interrupter and guide plate assembly relative to the secondary contact member 41 automatically as the latter is moved relative to the primary contact 26. Thus (FIGS. 7 and 7a), a pivot pin 79 mounts the outer end of a closing lever 80 on the secondary contact member 41 adjacent the end of the latter contacting the sleeve 33. Adjacent the inner end of this lever is an upstanding catch 81 arranged for releasable engagement with a pin 82 projecting downwardly from the U-shaped frame member 76. The pin extends freely through an elongated slot 83 in the secondary contact member and a registering slot 84 in the sleeve 33. A spring 85 is anchored at one end to the fixed pivot pin 79 and its opposite end engages the closing lever in such manner as to urge the latter resiliently toward the pin 82.

Also adjacent the inner end of the closing lever is a downwardly projecting tab 86 which supports a laterally extending pin 87. This pin cooperates with an opening lever 88 which is mounted at its outer end on the pivot screw 89 secured to the fixed transverse plate 35. The opening lever extends substantially parallel to the closing lever, between the laterally projecting pins 82 and 87 on the frame member 76 and closing lever 80, respectively. The opening lever also underlies a pin 90 projecting laterally from the secondary contact member 41. A spring 91 connects the opening lever to the plate 35 and biases the lever resiliently toward the pins 82 and 90.

The opening lever is provided with an upstanding catch 92 intermediate its ends for releasable engagement with the pin 82, and an upstanding cam section 93 adjacent its inner end for releasable engagement with the pin 90. The opening lever also is provided with a downwardly projecting cam section 94 arranged for releasable engagement with the pin 87 on the closing lever.

As the secondary contact member 41 moves inward from the position illustrated in FIG. 3 to the solid line position illustrated in FIG. 4, the catch 81 on the closing lever 80 engages behind the pin 82. Thus, the interrupter assembly moves inward with the secondary contact member until the primary contactor element 62 engages the primary contact 26. Upon further inward movement of the secondary contact member to the position illustrated in FIG. 5, the pin 87 on the closing lever engages the cam section 94 on the opening lever and the pin 90 on the secondary contact member engages the cam section 93. Both levers thus are cammed downward, retracting the catches 81 and 92 from the pin 82 and permitting the secondary contact member to move inward while the interrupter assembly remains stationary.

The foregoing sequence is reversed during movement of the secondary contact member away from the primary contact 26.

Means also is provided for opening and closing the interrupter contact elements 67 and 68 automatically as the secondary contact member 41 moves relative to the primary contact 26. Supported pivotally by the pivot pin 95 on the frame member 76 adjacent the outer guide plate 77 is a hub 96 (FIG. 6) which secures one end of each of a pair of laterally spaced toggle links 97. The opposite ends of these links are connected pivotally by the pivot pin 98 to the overlapping ends of a second pair of toggle links 99. The opposite ends of these toggle links are connected pivotally by the pivot screws 100 to the projecting arms 101 of a U-shaped yoke member 102 (FIG. 9). The closed end of this yoke member has a longitudinal threaded opening which receives the externally threaded adjustment sleeve 103. This sleeve is adjustable longitudinally with respect to the yoke member, and is secured in desired position of adjustment by such means as the set screw 104.

Slidable within the sleeve 103 is a connector sleeve 105 provided at its inner end with an enlarged collar 106. Interposed between this collar and the adjacent end of the adjustment sleeve is a rubber bushing 107 confined between spaced washers. The connector sleeve 105 is threaded internally for connection of the threaded projecting end of the stem 69. A set screw 108 may be tightened against the terminal end of the stem within the sleeve to secure it against rotation.

Surrounding the projecting portion of the stem 69 between the collar 106 and the inner guide plate 73, is a coil spring 109 which functions to urge the stern outward to the open position of the vacuum interrupter contacts (FIG. 3).

Formed integrally with the toggle links 97, through the common hub 96, is an operating lever 110 which pivots with the toggle links on the pivot pin 95. The upper surface of this lever is provided with an inner flat section and an outer projection 111 separated by a recess 112. The flat section and the projection are disposed for engagement with a transverse operating pin 113 which extends across the secondary contact member 41 and is secured removably therein by the set screw 114 (FIG. 8).

By movement of the operating-pin 113 inwardly from the recess 112 and along the fiat section of the operating lever 110 (FIGS. 3 and 4), the latter and the connected toggle links 97 are caused to rotate clockwise to the position of maximum extension of the toggle links 97 and 99. In this position, as best shown in FIG. 5, the pin 98 connecting the toggle links has moved slightly past the center line between the pins 95 and 100. Here, the links are locked against inadvertent opening, and are restricted against further downward movement by abutment against the transverse stop pin 115. In this position of the toggle links the connected stem 69 is moved inward to bring its contact 68 firmly into engagement with the associated fixed contact 67. The contact pressure between the engaging contacts is adjustable by the adjustable sleeve 103, and the resilience of the rubber bushing insures positive contact even though the stem 69 is retracted slightly as the pin 98 moves past center.

Electrical connection between the contact 68 and the terminal post 29 is provided by the pair of electrical cables 78 and 78, as previously mentioned. Cable 78 is connected at one end (FIG. 9) to the stem 69 of contact 68, as by means of an eyelet interposed between the collar 106 and the adjacent washer of the bushing 107. The opposite end of the cable is secured behind one of the nuts 75 engaging the guide member 73 to which the inner frame member 76 is secured. The second electrical cable 78 is secured at one end, as by means of a screw, to the outer guide member 77 and at the opposite end behind the inner nut 34 on the shank 30 of the post 29. The cables are long enough to accommodate the relative movement between the interconnected components.

When the pin 113 is moved toward the outer end of the lever 110, it engages the projection 111 and initiates counterclockwise rotation of the lever and connected toggle links 97. When the pivot connection 98 between the toggle links moves upward across the center line between the pivots 95 and 100, the coil spring 109 functions to accelerate the movement rapidly to collapse the toggle links and draw the contact stem 69 outward rapidly to break the contacts 67 and 68 of the vacuum interrupter. The limit of collapse of the toggle links, and hence the limit of opening of the interrupter contacts, is adjustable by means of the adjustment screw 116 mounted in an outward extension 117 of the lever 110 and positioned for abutment against the outer guide plate 77 (FIGS. 3 and 4).

The cooperative relationship of the components described hereinbefore is best explained by the following description of the operation of the switch: Let it be assumed that the terminal posts 23 and 29 are connected to a high voltage circuit and that the switch initially is in the open position illustrated in FIG. 3. Assuming it is desired to close the switch, the operator engages the tool (FIG. with the projecting pins 50 of the bell crank lever and rotates the tool counterclockwise (FIG. 1) to move the secondary contact member 41 toward the primary contact 26. The vacuum interrupter and associated operating mechanism moves with the secondary contact member until the primary contactor element 62 engages the primary contact. In this partially open position of the switch the components are in the positions illustrated in solid lines in FIG. 4. In this position the pin 82 projecting from the frame member 76 has moved inward over the upwardly projecting tab 92 on the opening lever 88 and the pin 90 projecting from the secondary contact member has moved inwardly over the cam section 93 of the opening lever. Movement of these pins to this intermediate position has been accommodated by resilient downward deflection of the opening lever against the resistance of the biasing spring 91.

Further, in this partially open position, the toggle links 97 and 99 are in the collapsed position, with the vacuum interrupter contacts 67' and 68 spaced apart, and the inner end of the secondary contact member 41 is spaced outwardly from the associated contactor element 63. This latter condition of spacing preferably is made visible to the operator through a window provided by the opening 118 in the top wall 13 of the housing. This opening is positioned for viewing the primary contact and adjacent area, and is sealed by a glass or other transparent cover 119 secured over the opening as by the screw 120.

As the operator continues to rotate the tool counterclockwise to complete closure of the switch, the secondary contact member 41 now moves inward relative to the interrupter assembly. During this movement, the pin 87 on the closing lever engages the downwardly projecting cam 94 on the opening lever 88, pivoting the closing lever clockwise (FIG. 7a) to retract the catch 81 below the pin 82 and thus allow the closing lever to move inward relative to the pin 82 which now'remains stationary with the interrupter assembly. Simultaneously, the operating pin 113 moves inward with the secondary contact member 41, engaging the fiat portion of the operating lever 110 and causing the latter and the connected toggle links to pivot clockwise to the broken line position illustrated in FIG. 4.

It will be observed from the broken lines in FIG. 4 that when the operating pin 113 reaches the position at which the toggle links operate to close the contacts 67 and 68 of the interrupter, the inner end of the secondary contact member 41 still is spaced a considerable distance outward from the secondary cont-actor element 63. The electric circuit thus is completed from the terminal post 23 through the primary contact 26 and the engaging primary contactor element 62, thence through the closed contacts of the vacuum interrupter, through the stem 69, cable 78, guide member 73, frame member 76, guide member 77 and conductor cable 78, thence through the shank 30 to the other terminal post 29.

The circuit having thus been made initially through the protection of the vacuum interrupter contacts, continued movement of the secondary contact member 41 into positive engagement with the secondary contactor element 63 completes the closure of the switch. This is visually observed through the window 119, as explained hereinbefore.

Breaking of a high voltage electric circuit is accomplished by reversing the procedure described hereinbefore. During initial clockwise rotation of the tool and the bell crank lever, the secondary contact member 41 is retracted from engagement with the secondary contactor element 63 while the interrupter assembly is held against movement by engagement of the pin 82 against the catch 92 on the opening lever 88. Thus, the electric circuit is maintained through the vacuum interrupter contacts and the conductor cable. When the operator pin 113 engages the projection 111 on the lever 110, the latter and the connected toggle links are rotated counterclockwise, moving the pivot pin 98 upward over the center line between the pivot pins 95 and 100. The spring 109 thereupon collapses the toggle links rapidly, quickly separating the interrupter contacts 67 and 68 to effect opening of the electric circuit. Further outward movement of the secondary contact member to the position of FIG. 3 is accommodated by engagement of pin with the cam section 93, thereby retracting the catch 92 on the opening lever 88 and allowing the pin 82 and interrupter assembly to move outward with the secondary contact member 41.

A plurality of the electric switches described hereinbefore may be assembled together as a composite unit for use as a double throw switch, a throw over switch, a selector switch, etc, with all switches operated by a single control. One such arrangement is illustrated in FIG. 11, wherein the housing is shown supporting three switches. The central switch 121 is supported between laterally spaced, electrically non-conductive rods 122 and 123 by means of the longitudinally spaced brackets 124 projecting laterally in opposite directions from the secondary contact member 41. One (125) of the other two switches disposed to one side of the central switch is similarly mounted by brackets 126 slidably engaging the electrically nonconductive rod 122 and the laterally spaced non-conductive rod 127. These brackets are disposed between the brackets 124 supporting the central switch, so as to be moved by the latter.

In similar manner the other switch 128 disposed to the opposite side of the central switch, is mounted by brackets 129 slidably engaging the electrically non-conductive rod 123 and the spaced electrically non-conductive rod 130, these brackets also being disposed inward of the brackets 124 supporting the central switch. The operating link 45 and associated bell crank lever is connected to the secondary contact member 41 of the central switch, whereupon movement of latter efiects simultaneous movement of the secondary contact members of the other two switches, as will be apparent.

Although the switch of the present invention may be mounted for use above ground, it is particularly suited to installation below ground, as in a concrete encasement with the bell crank extension and window exposed for use. In any event the switch is of compact construction, requiring a minimum of space for installation.

It will be apparent to those skilled in the art that various changes in the size, shape, number and arrangement of parts described hereinbefore may be made without departing from the spirit of this invention and the scope of the appended claims.

Having now described my invention and the manner in which it may be used, what I claim as new and desire to secure by Letters Patent is:

1. An electric switch comprising (a) a housing,

(b) a pair of terminal members supported by the housing in spaced apart relation,

(c) a primary contact member engaging one of the terminal members,

(d) a secondary contact member engaging the other terminal member and movable relative to the primary contact member,

(e) a movable vacuum interrupter member having a fixed contact and a movable contact,

(f) contactor means connected to the fixed contact of the interrupter member and arranged for releasable engagement selectively with the primary contact member and secondary contact member, and

(g) conductor means interconnecting the movable contact .of the interrupter member and the terminal member engaging the secondary contact member.

2. The electric switch of claim 1 including means interengaging the interrupter member and secondary contact member for simultaneous movement over a predetermined movement of the secondary contact member toward the primary contact member.

3. The electric switch of claim 2 wherein the interengaging means comprises retractable catch means movable with the secondary contact member, and stop means on the interrupter member arranged for releasable engagement by the catch means.

4. The electric switch of claim 1 including means interengaging the interrupter member and housing for securing the interrupter member against movement during the predetermined movement of the secondary member away from the primary contact member.

5. The electric switch of claim 4 wherein the interengaging means comprises retractable catch means fixed relative to the housing, and stop means on the interrupter member arranged for releasable engagement by the catch means.

6. The electric switch of claim 5 including cam and cam operator means on the secondary contact member and catch means arranged for interengagement during movement of the secondary contact member away from the primary contact member for retracting the catch means.

7. The electric switch of claim 1 including (a) means interengaging the interrupter member and secondary contact member for simultaneous movement over a predetermined movement of the secondary contact member toward the primary contact member, and

(b) means interengaging the interrupter member and housing for securing the interrupter member against movement during a predetermined movement of the secondary contact member away from the primary contact member.

8. The electric switch of claim 7 wherein (a) the means interengaging the interrupter member and secondary contact member comprises retractable catch means movable with the secondary contact member, and stop means on the interrupter member arranged for releasable engagement by the catch means,

(b) the means interengaging the interrupter member and housing comprises retractable catch means fixed relative to the housing and arranged to engage the stop means on the interrupter member, and

(c) cam and cam operator means on both catch means are arranged for interengagement during a predetermined movement of the secondary contact member toward and away from the primary contact member for retracting the catch means movable with the secondary contact member.

9. The electric switch of claim 1 including means interengaging the secondary contact member and the movable contact of the interrupter member for moving said contact by the secondary contact member during movement of the latter while the interrupter member is held against movement therewith.

10. The electric switch of claim 9 wherein the interengaging means comprises lever means engaging the interrupter contact for moving the latter, and lever actuating means on the secondary contact member arranged to engage the lever means.

11. The electric switch of claim 1 including operator means engaging the secondary contact member and extending from the housing for actuation.

12. Electric switch of claim 1 including window means on the housing disposed for viewing the area on the primary contact member for visually observing the opening and closing of the switch.

13. An electric switch comprising (a) a housing,

(b) a plurality of spaced pairs of terminal members supported by the housing, the terminal members of each pair being arranged in spaced apart relation,

(c) a plurality of primary contact members each engaging one of each pair of said terminal members,

(d) a plurality of secondary contact members each engaging the other terminal member of each pair and movable relative to the associated primary contact member,

(e) a plurality of movable vacuum interrupter members each having a fixed contact and a movable contact,

(f) a plurality of contactor means one connected to each of the fixed contacts of the interrupter member and arranged for releasable engagement selectively 9 10 with the associated primary contact member and sec- References Cited (gg a ggf fi t yfif 623mm means each interconnecting UNITED STATES PATENTS the moi/able contact of a different one of the inter- 2,978,560 4/1961 Bates et a1 X rupter members and the associated: terminal member 5 312671247 8/1966 P 200-444 X engaging the secondary contact member, 3,268,696 8/1966 Lindell 200-144 X (h) operator means engaging one the secondary 3,303,309 2/1967 Flurscherrn et a1. 200144 contact members and extending from the housing for FOREIGN PATENTS m and 400,716 11/1933 Great Britain.

(i) means" interengaging the plurality of secondary con- 10 tact members for simultaneous movement thereof ROBERT MACON Primary Emmi-"en upon actuation of the operator means. 

1. AN ELECTRIC SWITCH COMPRISING (A) A HOUSING, (B) A PAIR OF TERMINAL MEMBERS SUPPORTED BY THE HOUSING IN SPACED APART RELATION, (C) A PRIMARY CONTACT MEMBER ENGAGING ONE OF THE TERMINAL MEMBERS, (D) A SECONDARY CONTACT MEMBER ENGAGING THE OTHER TERMINAL MEMBER AND MOVABLE RELATIVE TO THE PRIMARY CONTACT MEMBER, (E) A MOVABLE VACUUM INTERRUPTER MEMBER HAVING A FIXED CONTACT AND A MOVABLE CONTACT, (F) CONTACTOR MEANS CONNECTED TO THE FIXED CONTACT OF THE INTERRUPTER MEMBER AND ARRANGED FOR RELEASABLE ENGAGEMENT SELECTIVELY WITH THE PRIMARY CONTACT MEMBER AND SECONDARY CONTACT MEMBER, AND (G) CONDUCTOR MEANS INTERCONNECTING THE MOVABLE CONTACT OF THE INTERRUPTER MEMBER AND THE TERMINAL MEMBER ENGAGING THE SECONDARY CONTACT MEMBER. 